How Underpinning Actually Works: A Summary of the Process

Mass pour underpinning is the most commonly used method when undertaking basement conversion projects or strengthening the foundations of a property for structural reasons. Although it is not a job for the DIY enthusiast, owing to the excavation work and the fact that it may affect the structural integrity of your home, it is not a particularly complicated process and can be explained in a few easy-to-understand steps.

Underpinning a Toronto Property: What It Actually Involves

When you hire a local contractor to underpin your foundations, whether to make better use of your below grade space or to improve the structural integrity of your home, they will follow the steps below if they are using the mass pour method.

Site Survey – The first thing that your contractor will want to do is to survey your property in order to make sure that mass pour underpinning will meet your needs and will not cause any unexpected issues.

Application for Building Permit – If you are underpinning a Toronto property, you will need a building permit before the work can commence. Your contractor will draw up detailed plans and prepare all the necessary documentation to submit with your application to the local municipality.

Digging of Holes Under the Footing of Your Property – The concrete slab on which your foundation walls are standing is known as the footing and its purpose is to spread the load from the walls to the land on which your home is situated. Your contractor will dig holes underneath the footing in small sections, not all at once. The reason the holes are dug in small sections is because the footing is supporting your property!

Filling Holes with Concrete – After each hole has been excavated, it will then be filled with concrete. Non-shrink grout is often used to fill the last couple of inches of each hole, to avoid the possibility of air pockets forming between the footing and the new concrete underpinning. Once the first hole has been filled in this manner, the next one will be dug, and so the process continues.

Installation of Waterproofing Membrane – To protect your basement from water damage, a waterproof membrane will be added when underpinning your Toronto home. This will be done once the mass pour stage has been completed.

Backfilling and Interior Waterproofing – The exposed foundation walls will now be backfilled and the interior of your basement can then be waterproofed with a weeping tile system and strategically positioned drainage pipes.

These are the basic steps that your contractor will follow although there is a little more to the process than this. If you would like full details of what underpinning a Toronto home involves, or you would like us to prepare a proposal for the underpinning of your property, please do not hesitate to call us whenever you have a few minutes to spare. We have completed many such projects in the area and would be delighted to help you complete yours.